The overall objective of the proposed research is to study the effects of early visual deprivation on the primate oculomotor system. Specifically, we plan to use a combination of behavioral, anatomical and chronic electrophysiological techniques to study the changes in the structure and function of the rhesus monkey superior colliculus that occur as a result of early monocular lid-closure. Briefly, the following approaches will be used. The visual fields of normal and nonocularly deprived monkeys will be determined using an orienting response task. Secondly, the electrophysiological properties of superior colliculus cells (visual, visual-motor and eye movement related neurons) will be determined in normal and deprived monkeys. Finally, the morphological changes within the superior colliculus, lateral geniculate nucleus and visual cortex will be studied using a variety of anatomical techniques. It is hoped that the results of these investigations will afford us a more complete understanding of the processes involved in the normal and abnormal functioning of the oculomotor system.